CN116215154B

CN116215154B - Attitude control method, attitude control system and attitude control device of drive-by-wire chassis

Info

Publication number: CN116215154B
Application number: CN202310482874.4A
Authority: CN
Inventors: 施国标; 孙惠春; 曹景昭; 韩冲; 刘鑫旺
Original assignee: Shenzhen Automotive Research Institute of Beijing University of Technology
Current assignee: Shenzhen Automotive Research Institute of Beijing University of Technology
Priority date: 2023-05-04
Filing date: 2023-05-04
Publication date: 2023-07-14
Anticipated expiration: 2043-05-04
Also published as: CN116215154A

Abstract

A posture control method, a control system and a control device of a drive-by-wire chassis relate to the technical field of intelligent chassis of automobiles. According to the scheme, after the space position information of the wheels, the stress information of the connection point of the vehicle body and the chassis and the dynamic position information of the wheels are obtained, the running working condition of the vehicle is determined according to the information, whether the running working condition needs to enter a gesture protection mode is judged, after the entering is determined, the type of the needed gesture protection working condition is determined, and finally the chassis of the vehicle is gesture protected according to the determined type of the gesture protection working condition. Through the scheme, the attitude information of the four wheels and the stress information of the connecting points can be detected in real time, then the running condition of the vehicle is judged through the chassis domain controller according to the information, the control of the running attitude of the vehicle body is realized according to the running condition, the running attitude of the vehicle body is in a controlled state at any time, and the matched vehicle body can be kept stable in the running process.

Description

Attitude control method, attitude control system and attitude control device of drive-by-wire chassis

Technical Field

The invention relates to the technical field of intelligent chassis of automobiles, in particular to a posture control method, a control system and a control device of a drive-by-wire chassis.

Background

With the development of the intellectualization of automobiles, the demands of the automobiles on chassis systems are gradually increased, and besides the functions of bearing and driving, the chassis systems also need to have the ability of cognizing, pre-judging and controlling the interaction between wheels and the ground, and have the ability of managing the running state of the automobiles. The drive-by-wire chassis technology is taken as a new intelligent chassis technology, and is a technical stage which is necessary for the gradual intelligent of a chassis system.

At present, the mode of carrying out gesture optimization to the drive-by-wire chassis in the prior art is based on the whole automobile body of the existing passenger car to carry out gesture adjustment, and the method mainly carries out detection according to a plurality of sensors such as the existing wheel speed sensor, yaw angle and yaw rate sensor, automobile body height sensor and the like on the conventional passenger car, so that input data is obtained, but the arrangement and the architecture of each sensor are scattered, and communication is realized by being collected on a CAN bus after being received by different controllers, so that the problem of poor consistency and instantaneity is caused. Moreover, due to the limitation of the installation and arrangement of the existing sensors, the gesture detection can only be carried out on the whole vehicle body, and for a drive-by-wire chassis system which is respectively developed by a chassis and a vehicle body cabin, the running gesture of the drive-by-wire chassis system cannot be ensured to be in a controlled state at any time, so that the gesture of the vehicle body cannot be kept stable in the running process easily.

Disclosure of Invention

The invention provides a gesture control method, a gesture control system and a gesture control device of a drive-by-wire chassis, which solve the problem that the gesture of a vehicle body cannot be kept stable in the running process because the drive-by-wire chassis system cannot be controlled at the running gesture in the prior art.

According to a first aspect, in one embodiment, there is provided a method for controlling an attitude of a drive-by-wire chassis, including:

acquiring space position information of wheels, stress information of a connecting point of a vehicle body and a chassis and dynamic position information of the wheels; the spatial position information of the wheels comprises spatial position information between coaxial wheels and/or spatial position information between wheels on the same side; the dynamic position information of the wheel comprises speed information and acceleration information of the wheel; the stress information at the connection point of the vehicle body and the chassis comprises stress information at the connection point of the suspension and the vehicle body;

determining the running condition of the vehicle according to the space position information of the wheels, the stress information of the connection point of the vehicle body and the chassis and the dynamic position information of the wheels; the running conditions of the vehicle comprise a straight uniform running condition and other conditions;

judging whether the running working condition of the vehicle is other working conditions, if so, determining that the chassis of the vehicle enters a posture protection mode;

After the chassis of the vehicle enters a posture protection mode, determining the posture protection working condition type of the chassis according to the other working conditions; the gesture protection working condition type of the chassis comprises a coaxial compensation protection working condition, a same-side compensation protection working condition and a coaxial same-side compensation protection working condition;

and performing gesture protection on the chassis according to the determined gesture protection working condition type.

In one embodiment, the other working conditions include a pothole road surface driving condition, an over-deceleration strip driving condition, a tilting driving condition, a unsteady driving condition, an up-down slope driving condition and a load uneven driving condition; the determining the gesture protection working condition type of the chassis according to the running working condition of the vehicle comprises the following steps:

when the running working condition of the vehicle is the over-deceleration strip running working condition or the uphill and downhill running working condition, determining that the gesture protection working condition type of the chassis is a coaxial compensation protection working condition;

when the running working condition of the vehicle is a tilting running working condition, determining that the posture protection working condition type of the chassis is a same-side compensation protection working condition;

when the running working condition of the vehicle is a pothole road running working condition, a unsteady running working condition or a non-uniform loading running working condition, determining that the posture protection working condition type of the chassis is a coaxial same-side compensation protection working condition.

In one embodiment, the determining that the type of the attitude protection condition of the chassis is a coaxial compensation protection condition includes:

obtaining the deviation value of the vertical position between the wheels on the same side, and obtaining the deviation value of the vertical position between the wheels on two groups of wheels on the same side;

and comparing the deviation values of the vertical positions between the two groups of wheels on the same side with a first threshold value respectively, and determining that the attitude protection working condition type of the chassis is coaxial compensation protection working condition when the deviation values of the vertical positions between the two groups of wheels on the same side are both larger than the first threshold value and the deviation values of the vertical positions between the two groups of wheels on the same side are the same.

In one embodiment, the determining that the type of the attitude protection condition of the chassis is a ipsilateral compensation protection condition includes:

obtaining deviation values of vertical positions among all the coaxial wheels, and obtaining deviation values of vertical positions among at least two groups of coaxial wheels;

and comparing the deviation values of the vertical positions between at least two groups of coaxial wheels with a second threshold value respectively, and determining that the posture protection working condition type of the chassis is the same-side compensation protection working condition when the deviation values of the vertical positions between at least two groups of coaxial wheels are both larger than the second threshold value and the deviation values of the vertical positions between at least two groups of coaxial wheels are both the same.

In one embodiment, the determining that the type of the attitude protection condition of the chassis is a coaxial ipsilateral compensation protection condition includes:

the stress information of the connection point of the suspension and the vehicle body is obtained;

if the stress information at the connection point of the suspension and the vehicle body changes irregularly, determining that the posture protection working condition type of the chassis is a coaxial same-side compensation protection working condition;

or alternatively, the first and second heat exchangers may be,

the stress information of all the connection points of the suspension and the vehicle body is obtained;

and comparing the stress information of all the suspension frames and the vehicle body connection points, and if the stress information of the suspension frames and the vehicle body connection points has a difference, and the difference value is larger than a preset value, determining that the posture protection working condition type of the chassis is a coaxial same-side compensation protection working condition.

In one embodiment, the performing gesture protection on the chassis according to the determined gesture protection working condition type includes:

when the gesture protection working condition type is a coaxial compensation protection working condition, performing displacement closed-loop control on the suspension of the coaxial wheels according to the deviation value of the vertical position between the wheels on the same side;

when the gesture protection working condition type is the same-side compensation protection working condition, carrying out displacement closed-loop control on the suspension of the wheels on the same side according to the deviation value of the vertical position between the coaxial wheels;

When the gesture protection working condition type is a coaxial same-side compensation protection working condition, stress information at the connection points of all the suspensions and the vehicle body before entering the driving working condition and stress information at the connection points of all the suspensions and the vehicle body after entering the driving working condition are obtained; respectively carrying out difference on stress information at the connecting point of the suspension and the vehicle body before entering the driving working condition and stress information at the same connecting point after entering the driving working condition to obtain a plurality of difference signals; filtering each difference signal, and performing map conversion on the filtered difference signals to obtain suspension compensation force; and carrying out suspension force closed-loop control on the suspension at the corresponding connection point according to the suspension compensation force.

In one embodiment, after the performing gesture protection on the chassis according to the determined gesture protection working condition type, the method further includes:

detecting the running condition of a vehicle, and judging whether the running condition of the vehicle is changed into a straight uniform running condition; if yes, ending the gesture protection mode;

otherwise, continuing to carry out gesture protection on the chassis according to the determined gesture protection working condition type until the running working condition of the vehicle is changed into a straight-line uniform-speed running working condition.

According to a second aspect, in one embodiment there is provided a attitude control system for a drive-by-wire chassis, comprising:

the acquisition module is used for acquiring the space position information of the wheels, the stress information of the connection points of the vehicle body and the chassis and the dynamic position information of the wheels; the spatial position information of the wheels comprises spatial position information between coaxial wheels and/or spatial position information between wheels on the same side; the dynamic position information of the wheel comprises speed information and acceleration information of the wheel;

the vehicle running condition determining module is used for determining the running condition of the vehicle according to the space position information of the wheels, the stress information of the connection point of the vehicle body and the chassis and the dynamic position information of the wheels; the running conditions of the vehicle comprise a straight uniform running condition and other conditions;

the judging module is used for judging whether the running working condition of the vehicle is other working conditions or not, if so, determining that the chassis of the vehicle enters a gesture protection mode;

the gesture protection working condition type determining module is used for determining the gesture protection working condition type of the chassis according to the other working conditions after the chassis of the vehicle enters a gesture protection mode; the gesture protection working condition type of the chassis comprises a coaxial compensation protection working condition, a same-side compensation protection working condition and a coaxial same-side compensation protection working condition;

And the gesture protection module is used for performing gesture protection on the chassis according to the determined gesture protection working condition type.

According to a third aspect, in one embodiment, there is provided an attitude control device of a drive-by-wire chassis, where the attitude control device adopts the attitude control system described above, and the attitude control device includes a chassis domain controller, an attitude detection assembly, a force sensor, a mounting distance adjusting plate, a connection circuit board, and a fixing device;

the attitude detection assembly is arranged on the frame close to the suspension through the fixing device and is used for detecting the space position information of the wheels and the dynamic position information of the wheels;

the installation distance adjusting plate is used for adjusting the position of the gesture detection assembly horizontally and axially;

the force sensor is arranged between the suspension and the vehicle body and is used for detecting stress information at the connection point of the vehicle body and the chassis;

the connecting circuit board is respectively and electrically connected with the gesture detection assembly and the force sensor, and is used for carrying out analog-to-digital conversion on information detected by the gesture detection assembly and the force sensor and communicating with the chassis domain controller;

The chassis domain controller is configured to:

In one embodiment, the attitude detection assembly includes a transverse axis correlation laser sensor, a longitudinal axis correlation laser sensor, and an attitude sensor;

the transverse axis correlation laser sensor is used for detecting vertical position information between coaxial wheels;

the longitudinal axis correlation laser sensor is used for detecting vertical position information between wheels on the same side;

The attitude sensor is used for detecting speed information and acceleration information of the wheel.

According to the attitude control method, the attitude control system and the attitude control device of the drive-by-wire chassis, after the spatial position information of the wheels, the stress information at the connection point of the vehicle body and the chassis and the dynamic position information of the wheels are obtained, the running condition of the vehicle is determined according to the spatial position information of the wheels, the stress information at the connection point of the vehicle body and the chassis and the dynamic position information of the wheels, whether the running condition needs to enter an attitude protection mode is judged, after the entering is confirmed, the needed attitude protection condition type is confirmed, and finally the chassis of the vehicle is subjected to attitude protection according to the confirmed attitude protection condition type. Through the scheme, the attitude information of the four wheels and the stress information of the connecting points can be detected in real time, then the running condition of the vehicle is judged through the chassis domain controller according to the information, the control of the running attitude of the vehicle body is realized according to the running condition, the running attitude of the vehicle body is in a controlled state at any time, and the matched vehicle body can be kept stable in the running process.

Drawings

Fig. 1 is a flowchart of a method for controlling the posture of a drive-by-wire chassis according to the present embodiment;

FIG. 2 is a flowchart I of determining the type of gesture protection condition provided in this embodiment;

FIG. 3 is a second flowchart for determining the type of gesture protection condition according to the present embodiment;

FIG. 4 is a third flowchart for determining the type of gesture protection conditions according to the present embodiment;

FIG. 5 is a fourth flowchart for determining the type of gesture protection conditions according to the present embodiment;

fig. 6 is a flowchart two of a gesture control method of a drive-by-wire chassis provided in the present embodiment;

fig. 7 is a block diagram of the attitude control system of the drive-by-wire chassis according to the present embodiment;

fig. 8 is a schematic structural diagram of an attitude control device of a drive-by-wire chassis according to the present embodiment.

Reference numerals: 100. an acquisition module; 200. the vehicle driving condition determining module; 300. a judging module; 400. the gesture protection working condition type determining module; 500. a gesture protection module; 1. mounting a distance adjusting plate; 2. a fixing device; 3. a gesture detection component; 31. a transverse axis correlation laser sensor; 32. an attitude sensor; 33. a longitudinal axis correlation laser sensor; 4. a connecting plate; 5. a force sensor; 6. chassis domain controller.

Detailed Description

The invention will be described in further detail below with reference to the drawings by means of specific embodiments. Wherein like elements in different embodiments are numbered alike in association. In the following embodiments, numerous specific details are set forth in order to provide a better understanding of the present application. However, one skilled in the art will readily recognize that some of the features may be omitted, or replaced by other elements, materials, or methods in different situations. In some instances, some operations associated with the present application have not been shown or described in the specification to avoid obscuring the core portions of the present application, and may not be necessary for a person skilled in the art to describe in detail the relevant operations based on the description herein and the general knowledge of one skilled in the art.

Furthermore, the described features, operations, or characteristics of the description may be combined in any suitable manner in various embodiments. Also, various steps or acts in the method descriptions may be interchanged or modified in a manner apparent to those of ordinary skill in the art. Thus, the various orders in the description and drawings are for clarity of description of only certain embodiments, and are not meant to be required orders unless otherwise indicated.

The numbering of the components itself, e.g. "first", "second", etc., is used herein merely to distinguish between the described objects and does not have any sequential or technical meaning. The terms "coupled" and "connected," as used herein, are intended to encompass both direct and indirect coupling, unless otherwise indicated.

In the existing vehicle attitude control, passive adaptation and active prefabrication adjustment are mainly adopted, and the adjustment is mainly carried out in the transverse direction and the vertical direction by means of a suspension and an ESC (electronic stability control system) in an execution mode. For example, when a vehicle passes through a hollow or uneven road surface, passive shock absorption of a suspension is mainly relied on, oversteer and understeer of the vehicle during steering can be regulated by means of ESCs, and braking of the vehicle on the ice and snow road surface is mainly regulated by means of ABS (anti-lock braking system) functions of the ESCs, and a relatively dispersed regulation mode of the functions is unfavorable for posture regulation of the whole chassis. For the detection part of the attitude control, the input data is obtained by detecting a plurality of sensors such as a wheel speed sensor, a yaw angle and yaw angle speed sensor, a vehicle body height sensor and the like on the traditional passenger vehicle, but the arrangement and the architecture of each sensor are scattered, and the sensors are received by different controllers and then are concentrated on a CAN bus to realize communication, so that the problems of poor consistency and instantaneity are easily caused. Moreover, due to the limitation of the installation and arrangement of the existing sensors, the gesture detection can only be performed on the whole vehicle body, and for a drive-by-wire chassis system which is developed by respectively developing a chassis and a vehicle body cabin, the drive-by-wire chassis system cannot be independently developed as a single product. Therefore, in order to solve the above problems in the prior art, a posture control method, a control system and a control device of a drive-by-wire chassis are provided, and the posture adjustment for the stable running of a vehicle body is realized by controlling the horizontal position and the stress of the connection point of the chassis and the vehicle body.

As shown in fig. 1, the attitude control method of the drive-by-wire chassis provided in the embodiment includes the following steps:

step 100: the method comprises the steps that the space position information of wheels, stress information at the connection point of a vehicle body and a chassis and dynamic position information of the wheels are obtained through an obtaining module; the spatial position information of the wheels includes spatial position information between the coaxial wheels and/or spatial position information between the wheels on the same side; the dynamic position information of the wheel includes speed information and acceleration information of the wheel; the stress information at the connection point of the vehicle body and the chassis comprises stress information at the connection point of the suspension and the vehicle body.

The space position information between coaxial wheels is obtained by detecting the laser sensor through a transverse axis, the space position information between wheels on the same side is obtained by detecting the laser sensor through a longitudinal axis, the dynamic position information of the wheels is obtained by detecting an attitude sensor, and the stress information at the connection point of the suspension and the vehicle body is obtained by detecting a force sensor.

Step 200: the vehicle running condition determining module determines the running condition of the vehicle according to the space position information of the wheels, the stress information of the connection point of the vehicle body and the chassis and the dynamic position information of the wheels; the running conditions of the vehicle include straight uniform running conditions and other conditions.

Other working conditions include a pothole road surface running working condition, an over deceleration strip running working condition, a tilting running working condition, a unsteady running working condition, an up-down slope running working condition and a load uneven running working condition according to the requirements and the common working condition of the drive-by-wire chassis; when the running condition of the vehicle is the over-deceleration strip running condition or the uphill and downhill running condition, determining that the posture protection condition type of the chassis is a coaxial compensation protection condition; when the running working condition of the vehicle is a tilting running working condition, determining that the posture protection working condition type of the chassis is a same-side compensation protection working condition; when the running condition of the vehicle is a pothole road running condition, a unsteady running condition or a load uneven running condition, the posture protection condition type of the chassis is determined to be a coaxial same-side compensation protection condition.

Step 300: judging whether the running working conditions of the vehicle are other working conditions or not through a judging module, if so, entering a step 400: determining that the chassis of the vehicle enters a posture protection mode, otherwise, performing step 700: the vehicle normally runs.

After the chassis of the vehicle enters the posture protection mode, step 500 is performed: the attitude protection working condition type determining module determines the attitude protection working condition type of the chassis according to other working conditions; the gesture protection working condition types of the chassis comprise a coaxial compensation protection working condition, a same-side compensation protection working condition and a coaxial same-side compensation protection working condition.

Step 600: and the gesture protection module performs gesture protection on the chassis according to the determined gesture protection working condition type.

In this embodiment, after the acquiring module acquires the spatial position information of the wheel, the stress information at the connection point of the vehicle body and the chassis, and the dynamic position information of the wheel, the vehicle driving condition determining module determines the driving condition of the vehicle according to the spatial position information of the wheel, the stress information at the connection point of the vehicle body and the chassis, and the dynamic position information of the wheel, then the judging module judges whether the driving condition needs to enter a gesture protection mode, and when the driving condition needs to enter, the gesture protection condition type determining module determines the required gesture protection condition type, that is, the coaxial compensation protection condition, the same-side compensation protection condition or the coaxial same-side compensation protection condition, and finally the gesture protection module performs corresponding gesture protection on the chassis of the vehicle according to the determined gesture protection condition type to limit the possible operation causing unstable operation of the vehicle body, thereby finally realizing stable operation of the vehicle body. The scheme of the application mainly ensures that the vehicle body runs stably all the time by limiting the connection point of the chassis and the vehicle body, and the limitation is carried out by adjusting the actuating mechanism (namely the chassis domain controller) of the chassis and is irrelevant to the vehicle body. In fact, the chassis has no limitation on the load, load distribution, size and the like of the vehicle body, the stable running of the vehicle body can be ensured no matter what vehicle body is built on the chassis, and the running posture of the chassis is required to be regulated by an executing mechanism under the condition of ensuring no instability so as to meet the stable running of the vehicle body.

Because the spatial position information of the wheels, the stress information at the connection point of the vehicle body and the chassis and the dynamic position information of the wheels are required to be filtered and processed after being transmitted, whether attitude control is required or not can be judged, and the implementation is difficult to be carried out timely, whether the vehicle body enters a running working condition requiring attitude protection or not is judged timely by detecting the correlation laser sensor in the special attitude transmission assembly according to different coaxial protection working conditions and same-side protection working conditions. The specific judging mode is as follows:

specifically, as shown in fig. 2, the determination of the coaxial compensation protection working condition, that is, the determination of the over-deceleration strip running working condition and the up-down slope running working condition is realized by the following steps:

step 510: and obtaining the deviation value of the vertical position between the wheels on the same side, and obtaining the deviation value of the vertical position between the wheels on the same side of the two groups.

Step 511: the deviation values of the vertical positions between the two groups of wheels on the same side are respectively compared with a first threshold value.

Step 512: when the deviation values of the vertical positions between the two groups of wheels on the same side are larger than the first threshold value and the deviation values of the vertical positions between the two groups of wheels on the same side are the same, determining that the posture protection working condition type of the chassis is a coaxial compensation protection working condition.

Specifically, vertical position signals of wheels on the same side are detected, in general, a vehicle is provided with two groups of wheels on the same side, at least two wheels on each group of wheels on the same side are provided, in this embodiment, two groups of suspension vertical position signals of wheels on the same side are transmitted to a chassis domain controller, the chassis domain controller calculates deviation values between suspension vertical positions of the two groups of wheels on the same side respectively, then the deviation values between the suspension vertical positions of the two groups of wheels on the same side are compared with a first threshold respectively, and when the deviation values between the suspension vertical positions of the two groups of wheels on the same side are all larger than the first threshold, and the deviation values between the suspension vertical positions of the two groups of wheels on the same side are not large, the vehicle can be judged to enter a coaxial compensation protection working condition.

For example, when the vehicle passes through the deceleration strip, the wheels of the front axle and the rear axle sequentially increase the vertical position of the suspension, the longitudinal axes of the front axle and the rear axle are disconnected after the correlation laser of the correlation laser sensor is deviated, corresponding electric signals are generated, the electric signals are transmitted to the chassis domain controller through the connecting circuit board, and the chassis domain controller judges the running condition of the vehicle entering the deceleration strip according to the corresponding signals and the coaxial vertical position change information. For example, when the vehicle runs on an uphill or a downhill, the vertical positions of the front axle and the rear axle are shifted, the correlation laser signals of the front axle and the rear axle are shifted, the speed of the longitudinal wheels is larger or smaller than the expected speed, and the condition that the vehicle runs on the uphill or the downhill is judged according to the signals. The concrete steps are as follows: when detecting that the left-side correlation laser signal A1 of the vertical axis is in an Off state, the right-side vertical axis correlation laser signal B1 is in the Off state, sending the left-side vertical axis correlation laser signal A1 and the right-side vertical axis correlation laser signal B1 to a chassis domain controller through a connecting circuit board, immediately judging that other working conditions are entered after the chassis domain controller receives the signals, simultaneously, obtaining a signal absolute difference value Z1DV1 of a vertical position signal FLZ1 of a left front wheel and a vertical position signal RLZ1 of a left rear wheel by the chassis domain controller, and judging that the working conditions enter a deceleration strip working condition or an up-down slope driving working condition if the signal absolute difference value Z1DV2 of a vertical position signal FRZ1 of a right front wheel and a vertical position signal RRZ1 of a right rear wheel are both larger than a first threshold value and the two values are not large.

In one embodiment, as shown in fig. 3, the determination of the same-side compensation protection mode, i.e. the determination of the tilting driving mode, is achieved by the following steps:

step 520: and obtaining the deviation values of the vertical positions among all the coaxial wheels, and obtaining the deviation values of the vertical positions among at least two groups of coaxial wheels.

Step 521: the deviation values of the vertical positions between at least two groups of coaxial wheels are respectively compared with a second threshold value.

Step 522: and when the deviation values of the vertical positions between at least two groups of coaxial wheels are larger than the second threshold value and the deviation values of the vertical positions between at least two groups of coaxial wheels are identical, determining that the posture protection working condition type of the chassis is the same-side compensation protection working condition.

Specifically, vertical position signals of wheels located coaxially are detected, in general, a vehicle has at least two groups of coaxial wheels, each group of coaxial wheels has two wheels, in this embodiment, the vehicle has two groups of coaxial wheels as an example, suspension vertical position signals of the two groups of coaxial wheels are transmitted to a chassis domain controller, deviation values between suspension vertical positions of the two groups of coaxial wheels are calculated by the chassis domain controller respectively, then the deviation values between the suspension vertical positions of the two groups of coaxial wheels are compared with a second threshold value respectively, and when the deviation values between the suspension vertical positions of the two groups of coaxial wheels are all larger than the second threshold value, and the deviation values between the suspension vertical positions of the two groups of coaxial wheels are not much different, the vehicle can be judged to enter the same-side compensation protection working condition. The second threshold value in this embodiment may be the same as the first threshold value, or may be greater than or less than the first threshold value, where the setting of the first threshold value and the second threshold value is determined according to the specific running parameters of the vehicle, and this embodiment does not make excessive demands here.

For example, when a turn is performed or the pavement on two sides is uneven, the vehicle body is inclined due to the too fast centrifugal force or the different relative vertical positions of the pavement, the single-side vertical displacement change and the two-side correlation laser are disconnected after being deviated, corresponding electric signals are generated, the electric signals are transmitted to the chassis domain controller through the connecting circuit board, and the chassis domain controller judges the condition of entering the inclined running according to the single-side vertical position change and the corresponding signals. The concrete steps are as follows: when the front axle cross-axis correlation laser signal A2 is detected to be in an Off state, the rear axle cross-axis correlation laser signal B2 is detected to be in an Off state, the front axle correlation laser signal A2 and the rear axle correlation laser signal B2 are sent to the chassis domain controller through the connecting circuit board, the chassis domain controller immediately judges that other working conditions are entered after receiving the signals, meanwhile, the chassis domain controller obtains a signal absolute difference Z2DV1 of a vertical position signal FLZ1 of a left front wheel and a vertical position signal RLZ1 of a right front wheel, a signal absolute difference Z2DV2 of a vertical position signal FRZ1 of a right front wheel and a vertical position signal RRZ1 of a right rear wheel, and if the Z2DV1 and the Z2DV2 are both larger than a second threshold value and the two values are not large, the two values are used as judging that one of the roll-over working conditions is entered. Meanwhile, the chassis domain controller obtains a signal absolute difference Y3DV1 of a longitudinal acceleration signal FLY3 of the left front wheel and a longitudinal acceleration signal RLY3 of the right front wheel, and a signal absolute difference Y3DV2 of a longitudinal acceleration signal FRY of the right front wheel and a longitudinal acceleration signal RRY3 of the right rear wheel, and if both the Y3DV1 and the Y3DV2 are larger than a set threshold value and the difference of the two values is not large, the signal absolute difference is used as one of conditions for judging that the rolling condition of the deceleration strip is entered. And the condition that the vehicle enters the tilting running condition can be judged by meeting any one condition.

In one embodiment, as shown in fig. 4, the determination of the coaxial ipsilateral compensation protection condition, that is, the determination of the pothole road running condition, the unsteady running condition and the load uneven running condition is realized by the following steps:

step 530: and obtaining stress information at the connection point of the suspension and the vehicle body.

Step 531: if the stress information at the connection point of the suspension and the vehicle body changes irregularly, the type of the attitude protection working condition of the chassis is determined to be a coaxial same-side compensation protection working condition.

Or as shown in fig. 5, the type of the attitude protection condition of the chassis in step 500 is determined to be the coaxial ipsilateral compensation protection condition by the following steps:

step 532: and obtaining stress information of connection points of all suspensions and the vehicle body.

Step 533: and comparing stress information of all the suspensions at the connection points of the suspensions and the vehicle body.

Step 534: if the stress information at the connection point of the suspension and the vehicle body has a difference, and the difference value is larger than a preset value, determining that the posture protection working condition type of the chassis is a coaxial same-side compensation protection working condition.

In this embodiment, the determination of the coaxial ipsilateral compensation protection condition may be implemented in two manners, where the first manner is: the stress information of the connection point of the suspension and the vehicle body is acquired in real time and transmitted to the chassis domain controller, the chassis domain controller is used for judging the stress information, and if the stress information of the connection point generates irregular change in a period of time, the posture protection working condition type of the chassis is determined to be coaxial same-side compensation protection working condition. For example, when the vehicle is running on a hollow road, the change of the four-wheel spatial position signal cannot be detected as input, so that the vehicle can only be used as input according to the change of the force of the four-wheel stress points, and when the irregular change of the signal of the four-wheel force sensor is detected and the deviation of the longitudinal speed and the expected speed occurs, the vehicle is considered to enter the hollow road running condition. The concrete steps are as follows: and detecting that a plurality of correlation laser signals are switched back and forth for 1s in On and Off states or that a single signal is accidentally in Off states, and judging that the road surface pit driving working condition is entered.

The second mode is as follows: and acquiring stress information of the connection points of all the suspensions and the vehicle body, transmitting the stress information to the chassis domain controller, comparing the stress information of the connection points of all the suspensions and the vehicle body through the chassis domain controller, and determining that the posture protection working condition type of the chassis is a coaxial same-side compensation protection working condition if the stress information of the connection points of the suspensions and the vehicle body has a difference value which is larger than a preset value. For example, when the load on one end is removed in the continuous transportation process, the load on the other end causes overlarge load difference between the left and right sides or front and back sides of the vehicle body, so that impact is generated on a suspension, the vehicle body is possibly unstable or inclined in the transportation process, the stress condition of four wheels is detected under the condition that the vertical position of the four wheels is unchanged and the speed is uniform, the stress condition is transmitted to a chassis domain controller, and the chassis domain controller judges that the vehicle enters a load uneven running condition according to the difference of the stress condition of the four wheels. For example, when the road surface with an excessively low road adhesion coefficient is running, the vertical position of the four wheels is easy to be unchanged, but the running cannot be concentrated because the four wheels cannot obtain friction force by depending on the ground, the four wheels are stressed differently, and finally the phenomena of slipping, steering out of control and rollover are caused.

In one embodiment, performing gesture protection on the chassis according to the determined gesture protection operating mode type includes:

when the gesture protection working condition type is the coaxial compensation protection working condition, the suspension of the coaxial wheels is subjected to displacement closed-loop control according to the deviation value of the vertical position between the wheels on the same side.

Specifically, after the vehicle is determined to enter the coaxial compensation protection working condition according to the judging method, the coaxial compensation function is started. If the vehicle runs through the speed reducing zone, the height of the front axle or the rear axle at the vertical position of the suspension is reduced when the front axle or the rear axle passes through the speed reducing zone, so that the vehicle body can keep running horizontally and stably. The method comprises the following steps: based On the Z1DV1 signal and the Z1DV2 signal, when the front wheels pass through a deceleration strip, a left front wheel suspension mechanism and a right front wheel suspension mechanism of the front axle perform displacement closed-loop control, so that the suspension height of the front axle is reduced, the front and rear axle body is ensured to be horizontal, and a left longitudinal axis correlation laser signal A1 and a right longitudinal axis correlation laser signal B1 are controlled to be in an On state; when the rear wheel passes through the deceleration strip, displacement closed-loop control is carried out On a left rear wheel suspension mechanism and a right rear wheel suspension mechanism of the rear axle, and the suspension height of the rear axle is reduced, so that the front and rear axle body is ensured to be horizontal, and after the control is finished, a left longitudinal axis correlation laser signal A1 and a right longitudinal axis correlation laser signal B1 are in an On state. The judgment of the front wheel and the rear wheel passing through the deceleration strip is carried out by the positive and negative of the Z1DV1 and Z1DV2 signal values.

If the vehicle is in the condition of ascending and descending slope, the vertical position of the suspension of the front axle or the rear axle is increased, the driving force of the driving mechanism is increased or decreased according to the expected speed, and the steering change rate of the steering mechanism is limited. Due to the limitation of the suspension system of the current chassis, the up-down slope protection of the chassis can only ensure the slope of the slope within +/-15 degrees, and when the slope exceeds the maximum angle, the compensation can only be carried out according to the maximum compensation angle. The detection principle of the specific longitudinal axis laser sensor is the same as the detection principle of the driving condition of the over-deceleration strip, and redundant description is omitted here.

When the posture protection working condition is the same-side compensation protection working condition, the suspension of the wheels on the same side is subjected to displacement closed-loop control according to the deviation value of the vertical position between the coaxial wheels.

Specifically, after the condition that the vehicle enters the same-side compensation protection working condition is determined according to the judging method, the same-side compensation function is started. When the suspension height of one side of the vehicle body is lower, the vertical position of the suspension of the other side is increased, and the steering change rate of the steering mechanism is limited, so that the vehicle body keeps running horizontally and stably. The method comprises the following steps: based on the signals Z2DV1, Z2DV2 or Y3DV1 and Y3DV2, when the left side is inclined, the left side wheel is controlled to increase the suspension height, the right side wheel is controlled to decrease the suspension height, the compensation value is output in an equal ratio mode according to the input signals, and the height ratio is in a compensation mode of 2:8, and meanwhile the steering speed of the steering mechanism is limited. When the right side is inclined, the right side wheel is controlled to increase the suspension height, the left side wheel is controlled to decrease the suspension height, the compensation value is output in an equal ratio mode according to the input signal, the height ratio is in a compensation mode of 2:8, and meanwhile the steering speed of the steering mechanism is limited, so that the running stability of the vehicle body is ensured.

When the gesture protection working condition type is the coaxial same-side compensation protection working condition, stress information of the connection points of all suspensions and the vehicle body before entering the driving working condition and stress information of the connection points of all suspensions and the vehicle body after entering the driving working condition are obtained; respectively carrying out difference on stress information at a connecting point of the suspension and the vehicle body before entering a driving working condition and stress information at the same connecting point after entering the driving working condition to obtain a plurality of difference signals; filtering each difference signal, and performing map conversion on the filtered difference signals to obtain suspension compensation force; and carrying out suspension force closed-loop control on the suspension at the corresponding connection point according to the suspension compensation force.

Specifically, after the vehicle is determined to enter the coaxial ipsilateral compensation protection working condition according to the judging method, the coaxial ipsilateral compensation function is started. If the vehicle is in an unstable running working condition, the longitudinal speed is reduced according to the step degree, the change rate of the steering mechanism is limited, the four-wheel stress at the suspension is regulated, and the four-wheel stress point is balanced as much as possible under the condition that the vehicle body is not excessively inclined. If the load is in the non-uniform running condition, judging whether the vehicle enters the same side or is in coaxial compensation according to the difference of the load, and continuously applying a part of force to the suspension to ensure the stable running of the vehicle body. And if the vehicle runs on the hollow road, the suspension generates reverse force to resist the impact of the hollow road by filtering the signals of the force sensor, so that the vehicle body is kept level and stable as much as possible. In this embodiment, when a driving condition of a hollow road is taken as an example, compensation cannot be performed by means of position or speed signals at this time when the driving condition of the hollow road is entered, so that a left front wheel force sensor signal FLT1, a right front wheel force sensor signal FRT1, a left rear wheel force sensor signal RLT1 and a right rear wheel force sensor signal RRT1 are collected, these signals are transmitted to a chassis domain controller, the chassis domain controller obtains difference signals FLT1DV1, FRT1DV1, RLT1DV1 and RRT1DV1 according to differences between the signals and the values of the signals before entering the working condition, respectively performs low-pass filtering processing on the differences, filters clutter below 5HZ, performs map conversion on the obtained data to obtain suspension compensation force, performs suspension force closed-loop control by the suspension compensation force, controls suspension to perform accurate force compensation processing, and simultaneously limits steering speed of a steering mechanism to offset unstable fluctuation, thereby ensuring stable running of a vehicle body.

In one embodiment, referring to fig. 6, after performing posture protection on the chassis according to the determined posture protection working condition type, the method further includes the following steps:

step 700: and detecting the running condition of the vehicle.

Step 800: judging whether the running condition of the vehicle is changed into a straight uniform running condition; if yes, go to step 110: and ending the gesture protection mode, and enabling the vehicle to enter a straight uniform-speed running working condition.

Otherwise, step 900 is performed: and continuing to carry out posture protection on the chassis according to the determined posture protection working condition type until the running working condition of the vehicle is changed into a straight-line uniform-speed running working condition.

In this embodiment, after the posture protection of the current running condition is completed, the posture control system further detects the running condition of the current vehicle, and only when detecting that the running condition of the vehicle is changed into a straight uniform running condition, the chassis running condition is indicated to be good, then the chassis posture is normally operated, the posture protection is finished, and the vehicle is normally operated. When the running condition of the vehicle is detected not to be changed into the straight uniform running condition, the vehicle is indicated to be still in the running condition at the previous moment or enters other conditions, and the attitude protection mode is continuously adopted to carry out attitude protection on the chassis until the running condition is changed into the straight uniform running condition.

As shown in fig. 7, the present embodiment provides a posture control system of a drive-by-wire chassis, which includes an acquisition module 100, a vehicle driving condition determining module 200, a judging module 300, a posture protection condition type determining module 400, and a posture protection module 500. The acquisition module 100 is used for acquiring the space position information of the wheels, the stress information of the connection points of the vehicle body and the chassis and the dynamic position information of the wheels; the spatial position information of the wheels includes spatial position information between the coaxial wheels and/or spatial position information between the wheels on the same side; the dynamic position information of the wheel includes speed information and acceleration information of the wheel. The vehicle running condition determining module 200 is used for determining the running condition of the vehicle according to the space position information of the wheels, the stress information of the connection points of the vehicle body and the chassis and the dynamic position information of the wheels; the running conditions of the vehicle include straight uniform running conditions and other conditions. The judging module 300 is configured to judge whether the driving condition of the vehicle is other conditions, and if yes, determine that the chassis of the vehicle enters the posture protection mode. The gesture protection working condition type determining module 400 is configured to determine a gesture protection working condition type of the chassis according to other working conditions after the chassis of the vehicle enters a gesture protection mode; the gesture protection working condition types of the chassis comprise a coaxial compensation protection working condition, a same-side compensation protection working condition and a coaxial same-side compensation protection working condition. The gesture protection module 500 is configured to perform gesture protection on the chassis according to the determined gesture protection working condition type.

Specifically, the specific roles and functions of the acquiring module 100, the vehicle driving condition determining module 200, the judging module 300, the gesture protection condition type determining module 400 and the gesture protection module 500 in this embodiment are described in detail in the above embodiments of the gesture control method, and this embodiment is not described in detail herein.

As shown in fig. 8, in the present embodiment, there is provided an attitude control apparatus of a drive-by-wire chassis, the attitude control apparatus including a chassis domain controller 6, an attitude detection assembly 3, a force sensor 5, a mounting trim panel 1, a connection circuit board, and a fixing device 2. Wherein, gesture detection subassembly 3 passes through fixing device 2 to be installed on the frame that is close to the suspension, and gesture detection subassembly 3 is used for detecting the spatial position information of wheel and the dynamic position information of wheel. The distance adjusting plate 1 is installed for performing position adjustment horizontally and axially on the attitude detecting assembly 3. A force sensor 5 is mounted between the suspension and the body for detecting force information at the connection point of the body to the chassis. The connecting circuit board is respectively and electrically connected with the gesture detection assembly 3 and the force sensor 5, and is used for carrying out analog-to-digital conversion on information detected by the gesture detection assembly 3 and the force sensor 5 and communicating with the chassis domain controller 6. The chassis domain controller 6 is configured to: determining the running condition of the vehicle according to the space position information of the wheels of the longitudinal axis correlation laser sensor 33, the stress information of the connection point of the vehicle body and the chassis and the dynamic position information of the wheels; the running conditions of the vehicle comprise a straight uniform running condition and other conditions; judging whether the running working conditions of the vehicle of the longitudinal axis opposite-emitting laser sensor 33 are other working conditions, if so, determining that the chassis of the vehicle of the longitudinal axis opposite-emitting laser sensor 33 enters a posture protection mode; after the chassis of the vehicle of the longitudinal axis opposite-shooting laser sensor 33 enters a posture protection mode, determining the posture protection working condition type of the chassis of the longitudinal axis opposite-shooting laser sensor 33 according to other working conditions of the longitudinal axis opposite-shooting laser sensor 33; the gesture protection working condition types of the chassis of the longitudinal axis opposite-shooting laser sensor 33 comprise a coaxial compensation protection working condition, a same-side compensation protection working condition and a coaxial same-side compensation protection working condition; and performing attitude protection on the chassis of the longitudinal axis opposite-shooting laser sensor 33 according to the determined attitude protection working condition type of the longitudinal axis opposite-shooting laser sensor 33.

Specifically, a posture detecting component 3, a force sensor 5 and a connecting circuit board are mounted on the frame near the connecting point of the suspension corresponding to each wheel and the vehicle body, wherein the posture detecting component 3, the force sensor 5 and the connecting circuit board are mounted on the frame through a fixing device 2. Before the vehicle leaves the factory or when the vehicle is overhauled, a technician can firstly carry out position adjustment on the gesture detection assembly 3 in the horizontal direction and the axial direction by installing the distance adjustment plate 1 so as to ensure that the transverse correlation laser sensors are positioned at the same horizontal position between coaxial wheels in the gesture detection assembly 3; and the longitudinal correlation laser sensors are positioned at the same horizontal position between the wheels at the same side, so that the gesture control device can work well in the practical application process. Then, in the working process of the gesture control device, the gesture detection assembly 3 and the force sensor 5 detect the space position information, the dynamic position information and the stress information of each wheel in real time, and timely transmit the space position information, the dynamic position information and the stress information of each wheel to the chassis domain controller 6 through the connection circuit board, and the gesture control system is controlled by the chassis domain controller 6 to carry out gesture protection on the chassis. The connection circuit board converts the analog voltage signals transmitted by the gesture detection assembly 3 and the force sensor 5 into digital signals and communicates with the chassis domain controller 6 through the CAN bus, and the connection circuit board CAN adopt the existing equipment (such as a digital-to-analog converter, an analog-to-digital converter and the like) to realize the functions; the fixing device 2 and the mounting adjusting plate 1 are also implemented by the existing equipment, and the embodiment does not have excessive requirements here. In this embodiment, the control method for protecting the chassis by the chassis domain controller 6 is described in detail in the above embodiment, and the embodiment is not described herein in detail.

Specifically, as shown in fig. 8, the attitude detection assembly 3 includes a horizontal axis correlation laser sensor 31, a vertical axis correlation laser sensor 33, and an attitude sensor 32; the transverse axis correlation laser sensor 31 is used for detecting vertical position information between coaxial wheels; the longitudinal axis correlation laser sensor 33 is used for detecting vertical position information between wheels on the same side; the attitude sensor 32 is used to detect speed information and acceleration information of the wheel.

In practical applications, the attitude detection assembly 3 detects the spatial position information of the wheels by the transverse axis correlation laser sensor 31 and the longitudinal axis correlation laser sensor 33, specifically, detects the vertical position information between the coaxial wheels by the transverse axis correlation laser sensor 31 and detects the vertical position information between the wheels on the same side by the longitudinal axis correlation laser sensor 33.

In the attitude detection assembly 3 of coaxial wheels, a transverse-axis correlation laser sensor 31 at one of the wheels is set as a transmitting end, a transverse-axis correlation laser sensor 31 at the other wheel is set as a receiving end, for example, as shown in fig. 8, a transverse-axis correlation laser sensor 31 at the left front wheel is set as a receiving end A2, a transverse-axis correlation laser sensor 31 at the right front wheel is set as a transmitting end A1, a transverse-axis correlation laser sensor 31 at the left rear wheel is set as a transmitting end B1, a transverse-axis correlation laser sensor 31 at the right rear wheel is set as a receiving end B2, wherein the transmitting end A1 and the receiving end A2 are used for detecting vertical position information between the left front wheel and the right front wheel, and the transmitting end B1 and the receiving end B2 are used for detecting vertical position information between the left rear wheel and the right rear wheel. In the attitude detection assembly 3 of the same-side wheels, a longitudinal axis correlation laser sensor 33 at one of the wheels is set as a transmitting end, a longitudinal axis correlation laser sensor 33 at the other wheel is set as a receiving end, for example, as shown in fig. 8, a longitudinal axis correlation laser sensor 33 at the left front wheel is set as a transmitting end A1, a longitudinal axis correlation laser sensor 33 at the left rear wheel is set as a receiving end A2, a longitudinal axis correlation laser sensor 33 at the right front wheel is set as a receiving end B2, a longitudinal axis correlation laser sensor 33 at the right rear wheel is set as a transmitting end B1, wherein the transmitting end A1 and the receiving end A2 are used for detecting vertical position information between the left front wheel and the left rear wheel, and the transmitting end B1 and the receiving end B2 are used for detecting vertical position information between the right front wheel and the right rear wheel.

When the laser component is used, the transmitting end of the correlation laser sensor can be accepted by the receiving end, and the receiving end can judge whether the two shafts are in the horizontal position or not and the horizontal error according to the correlation position of the transmitting end.

The attitude detection assembly 3 detects dynamic position information of the wheels through an attitude sensor 32. Specifically, the speed information and the acceleration information of the wheel are detected by the attitude sensor 32.

In addition, since the attitude protection is performed by detecting the stress of the vehicle body and chassis connection points and the spatial position and dynamic position data between four wheels, it is necessary to obtain a force signal of each connection point, the spatial position and information between the wheels, and an instant signal capable of determining that the chassis operation attitude is stable. Based on the gesture sensor 32 module commonly used in the market and the correlation laser sensors used for detecting parallelism in real time are combined in pairs, the four sensors meet the detection requirement of four-wheel areas, and force signals and position signals are separately detected due to the fact that the force of connecting points changes in real time, the force sensor 5 for detecting the force signals is independently installed, but the force signals and the position signals are uniformly received by the connecting circuit board, so that hardware cost is reduced.

The foregoing description of the invention has been presented for purposes of illustration and description, and is not intended to be limiting. Several simple deductions, modifications or substitutions may also be made by a person skilled in the art to which the invention pertains, based on the idea of the invention.

Claims

1. A posture control method of a drive-by-wire chassis, characterized by comprising:

2. The attitude control method of a drive-by-wire chassis according to claim 1, wherein the other conditions include a pothole road surface running condition, an over-deceleration strip running condition, a roll-over running condition, a unsteady running condition, an up-down slope running condition, and a load uneven running condition; the determining the gesture protection working condition type of the chassis according to the running working condition of the vehicle comprises the following steps:

3. The attitude control method of a drive-by-wire chassis of claim 2, wherein said determining that the type of attitude protection condition of the chassis is a coaxial compensation protection condition comprises:

4. The attitude control method of a drive-by-wire chassis of claim 3, wherein said determining that the type of attitude protection condition of the chassis is a ipsilateral compensation protection condition comprises:

5. The attitude control method of a drive-by-wire chassis of claim 4, wherein said determining that the type of attitude protection conditions of the chassis is a coaxial ipsilateral compensation protection condition comprises:

or alternatively, the first and second heat exchangers may be,

6. The attitude control method of a drive-by-wire chassis according to claim 5, wherein said attitude protecting the chassis according to the determined type of the attitude protecting condition includes:

7. The attitude control method of a drive-by-wire chassis according to claim 1, wherein after the chassis is attitude-protected according to the determined type of the attitude protection condition, further comprising:

detecting the running condition of the vehicle and judging whether the running condition of the vehicle is changed into a straight uniform running condition; if yes, ending the gesture protection mode;

8. A posture control system of a drive-by-wire chassis, characterized by comprising:

9. The gesture control device of the drive-by-wire chassis is characterized by comprising a chassis domain controller, a gesture detection assembly, a force sensor, a mounting distance adjusting plate, a connecting circuit board and a fixing device;

the chassis domain controller is configured to:

10. The attitude control apparatus of a drive-by-wire chassis of claim 9, wherein the attitude detection assembly includes a transverse axis correlation laser sensor, a longitudinal axis correlation laser sensor, and an attitude sensor;